Many different medical devices are passed through a lumen of a tubular body part for diagnostic and/or delivery purposes. An endoscope, for example, is an instrument that is used for visually examining the interior of a bodily canal or a hollow organ, such as the colon, bladder, stomach, or intestines. During a procedure involving use of an endoscope, the instrument must be carefully navigated through the tubular body part in order to avoid perforating the intraluminal wall of the body part.
Many techniques can be used to move an endoscope through a lumen. Most endoscopes are forced through the tubular body part and a mechanical articulation mechanism is used to manipulate the endoscope around turns. More recently, endoscopes have been developed that employ distal, intermediate, and proximal inflatable cuffs that are selectively inflated and deflated to effect migration of the distal end of the instrument through the lumen of a tubular body part. The distal cuff, which is secured to a sheath that surrounds the fibers used to obtain and transmit an image, is expanded radially while the proximal and intermediate cuffs are secured to the distal cuff, respectively, and are axially slidable on the sheath. The proximal cuff is expanded radially while the intermediate cuff is expand axially. While the use of expandable cuffs can be an effective propulsion mechanism to push and pull the device through a tubular body part, difficulty can be encountered when navigating sharp turns in the tubular body part. The inflatable cuffs do not provide for angular manipulation of the device.
Accordingly, there is a need for improved methods and devices for traversing a tubular body part.